<title> 低价回文</title><link href="http://hzoi.com/tomorrow.css" rel="stylesheet"><div class="ui existing segment"><pre><code><span class="pl-cp">#include</span><span class="pl-cpf">&lt;bits/stdc++.h&gt;</span><span class="pl-cp"></span>
<span class="pl-cp">#define inf 1e8</span>
<span class="pl-k">using</span> <span class="pl-k">namespace</span> <span class="pl-n">std</span><span class="pl-p">;</span>
<span class="pl-kt">int</span> <span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-mi">2020</span><span class="pl-p">][</span><span class="pl-mi">2020</span><span class="pl-p">];</span>
<span class="pl-kt">int</span> <span class="pl-nf">main</span><span class="pl-p">()</span> <span class="pl-p">{</span>
    <span class="pl-kt">int</span> <span class="pl-n">n</span><span class="pl-p">,</span><span class="pl-n">m</span><span class="pl-p">,</span><span class="pl-n">x</span><span class="pl-p">,</span><span class="pl-n">y</span><span class="pl-p">,</span><span class="pl-n">v</span><span class="pl-p">[</span><span class="pl-mi">30</span><span class="pl-p">];</span>
    <span class="pl-kt">char</span> <span class="pl-n">z</span><span class="pl-p">,</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-mi">2020</span><span class="pl-p">];</span>
    <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d%d&quot;</span><span class="pl-p">,</span><span class="pl-o">&amp;</span><span class="pl-n">n</span><span class="pl-p">,</span><span class="pl-o">&amp;</span><span class="pl-n">m</span><span class="pl-p">);</span>
    <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%s&quot;</span><span class="pl-p">,</span><span class="pl-n">a</span><span class="pl-p">);</span>
    <span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span><span class="pl-o">=</span><span class="pl-mi">0</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">&lt;</span><span class="pl-n">n</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">){</span>
        <span class="pl-n">cin</span><span class="pl-o">&gt;&gt;</span><span class="pl-n">z</span><span class="pl-o">&gt;&gt;</span><span class="pl-n">x</span><span class="pl-o">&gt;&gt;</span><span class="pl-n">y</span><span class="pl-p">;</span>
        <span class="pl-n">v</span><span class="pl-p">[</span><span class="pl-n">z</span><span class="pl-o">-</span><span class="pl-sc">&#39;a&#39;</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">min</span><span class="pl-p">(</span><span class="pl-n">x</span><span class="pl-p">,</span><span class="pl-n">y</span><span class="pl-p">);</span>
    <span class="pl-p">}</span>
    <span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">j</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">j</span><span class="pl-o">&lt;</span><span class="pl-n">m</span><span class="pl-p">;</span><span class="pl-n">j</span><span class="pl-o">++</span><span class="pl-p">){</span>
        <span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span><span class="pl-o">=</span><span class="pl-n">j</span><span class="pl-o">-</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">&gt;=</span><span class="pl-mi">0</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">--</span><span class="pl-p">){</span>
            <span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">inf</span><span class="pl-p">;</span>
            <span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span><span class="pl-o">==</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">j</span><span class="pl-p">])</span> <span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-o">-</span><span class="pl-mi">1</span><span class="pl-p">];</span>
            <span class="pl-k">else</span> <span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">min</span><span class="pl-p">(</span><span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-p">]</span><span class="pl-o">+</span><span class="pl-n">v</span><span class="pl-p">[</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span><span class="pl-o">-</span><span class="pl-sc">&#39;a&#39;</span><span class="pl-p">],</span><span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-o">-</span><span class="pl-mi">1</span><span class="pl-p">]</span><span class="pl-o">+</span><span class="pl-n">v</span><span class="pl-p">[</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">j</span><span class="pl-p">]</span><span class="pl-o">-</span><span class="pl-sc">&#39;a&#39;</span><span class="pl-p">]);</span>
        <span class="pl-p">}</span>
    <span class="pl-p">}</span>
    <span class="pl-n">printf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d</span><span class="pl-se">\n</span><span class="pl-s">&quot;</span><span class="pl-p">,</span><span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-mi">0</span><span class="pl-p">][</span><span class="pl-n">m</span><span class="pl-o">-</span><span class="pl-mi">1</span><span class="pl-p">]);</span>
    <span class="pl-k">return</span> <span class="pl-mi">0</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
 
</cpde></pre></div>